The present invention relates to an X-ray image detecting apparatus, and more particularly to an X-ray image detecting apparatus improved so as to provide a high-contrast X-ray image without taking a long time.
An X-ray image obtained by making X-rays penetrate the object with the rays given a conical expanse covering a predetermined entire area to be imaged, has its image contrast deteriorated under the influence of stray X-rays scattered from various portions within the object. A conventional way to avoid the contrast deterioration due to such stray X-rays is to complete an X-ray image by scanning an object onedimensionally with a thin flat X-ray beam diverging in the form of a fan, or preferably two-dimensionally with a thin linear X-ray beam, instead of radiating the object with a conically diverging flux of X-rays covering the entire expanse of the image. The stray X-rays can be decreased by decreasing the diverging solid angle of X-rays to be irradiated to the object. The decreased but still existing stray X-rays are prevented, for instance in case of the linear X-ray beam, with a pin-holed plate inserted between the object and an X-ray image receiving plane so as to make only the X-ray beam pass the pin hole provided to the above plate. However, such a conventional way is accompanied by an important disadvantage that it takes a long time to obtain a complete image owing to the period of time necessary for the scanning operation of the X-ray beam. In addition it is troublesome to make the pin-holed plate interlocked to the scanning movement of the X-ray beam.